The long-range goal of this research is a genetic and biochemical analysis of ion transport in Neurospora. Experiments during the next few years will focus on: (1) isolation and characterization of K transport mutants, and study of a membrane-bound ATPase which may be involved in transport; (2) kinetic analysis of PO4 transport in wild-type and mutant strains, and search for a related PO4-binding protein; and (3) measurement of K and PO4 uptake by isolated mitochondria, to see whether plasma-membrane transport systems and mitochondrial transport systems are under common genetic control. The results should help to understand the mechanism of ion transport in more complex eukaryotic cells, and are also relevant to the study of inherited transport diseases such as hereditary spherocytosis, cystic fibrosis, renal tubular acidosis, and familial hypophosphatemia.